Leonard Rose Ingersoll (1880-1958) was Professor of Physics at the University of Wisconsin-Madison from 1905-1950, and chair of the Physics Department from 1936-1947. He arrived in Madison as a graduate student in mathematics in 1901 but switched to physics a year later. His research focus was in the optical and magnetic properties of materials. The L.R. Ingersoll Museum and L.R. Ingersoll Prize are named in his honor.